The prior art is documented with techniques for flattening or leveling a base surface, such as a wooden subflooring or poured concrete foundation, and prior to the installation of a floor covering, such as a wood, carpet or laminate style material including but not limited to vinyl. In one known prior art application, asphalt roofing shingles has been used for “filling” in such depressions. Other “fill-in” compositions are known for use in filling a depression in a floor construction, one example of which being disclosed in U.S. Pat. No. 7,241,819 to Bowe.